Commission F has the title "Wave Propagation and Remote Sensing (including radio-meteorology, radio-oceanography and remote sensing of non-ionised media)" and as its terms of reference: "The Commission promotes research and development in:

1. The study of all aspects of wave propagation at all frequencies in a non-ionised environment: (i) wave propagation over the Earth’s surface, (ii) wave propagation in, and interaction with, the neutral atmosphere, (iii) wave interaction with the Earth’s surface, oceans, land and ice, (iv) wave propagation through, and scattering by, the subsurface medium, (v) characterisation of the environment as it affects wave phenomena;
2. The application of the results of these studies, particularly in the areas of remote sensing and communications;
3. The appropriate cooperation with other URSI Commissions and other relevant organisations.

Prime responsibilities this triennium, as previously, have been shared between the Chairman (Mr Martin P M Hall) and Vice Chairman (Dr Yoji Furuhama).

Setting up a scientific programme for a triennium is the prime activity of an URSI Commission in order to achieve an exchange of ideas and research results amongst individual scientists throughout the world. This is carried out at General Assemblies and other meetings.

At General Assemblies, Commission F selects (largely from proposals made at business meetings in the previous GA) a number of topics and convenors to cover specific matters of interest. The convenors are then given the responsibility to invite speakers to give a balance of scientific content and geographical representation. In the current triennium, there is a Commission F Tutorial entitled "Remote characterisation of geophysical phenomena using EM waves" and Commission F sessions entitled: "Mobile terrestrial and satellite propagation modelling" (F1) (RRS chapter), "Climatic parameters in radiowave propagation prediction" (F2) (RRS chapter), "Millimetric, sub-millimetric and optical wave propagation" (F3), "Remote and in-situ sensing of clouds and their effects on radiowave propagation" (F4), "Atmospheric dynamics in the lower atmosphere: Measurement, modelling and effects" (F5), "Spaceborne remote sensing of precipitation - TRMM" (F6) (RRS chapter), "Remote sensing of Earth surfaces" (F7) (RRS chapter), "Interferometric techniques in remote sensing" (F8) (RRS chapter), "Polarimetric techniques in remote sensing" (F9) and "Synergetic use of remote sensing instruments" (F10). There is also a poster session entitled "Wave propagation and remote sensing" (FP) to cover the whole subject area of the commission, and joint sessions entitled: "Techniques and applications for sub-surface remote sensing" (FAB), "Mobile and personal communications" (CF), "Interference in communication" (EF), "Ionosphere and troposphere parameters retrieved from GPS/GLONAS measurements" (GF), and "Tropospheric path delay correction" (JF). The sessions marked "RRS chapter" have chapters on that topic in the URSI book entitled "Review of Radio Science 1996-1999".

In addition there are the Workshop sessions on: "Interfacing propagation with transmission and antenna system studies for mobile/personal communications" (WSF1), "Synergy of active and passive remote sensing instuments" (WSF2) and "WISIP - Wideband (ULF to UV) Interferometric Sensing and Imaging Polarimetry - theory and applications" (WSF3). These are slightly different in nature and it is the first time that such workshops have been organised.

As to other meetings, between General Assemblies, Commission F has had a busy triennium, with 6 scheduled Mode B meetings (financial support requested) and 13 Mode A meetings (no financial support requested). The former comprised:

- ISRP: International Symposium on Radiowave Propagation; Qiangdao, China, 12-16 August 1997. (RSB Dec’97 pp 14-16)

- MST8: Eighth International Workshop on Technical and Scientific Aspects of MST Radar; Bangalore, India, 15-20 December 1997. (RSB June’98 pp 32-33)

- Microwave Signatures in Remote Sensing; Moscow, Russia, 11-13 March 1998, cancelled at short notice and grant returned in full.

- Climpara'98: Climatic Parameters in Radiowave Propagation Prediction; Ottawa, Ontario, Canada, 27-29 April 1998.

- Physics and Engineering of Millimetre and Submillimetre EM Waves; Kharkov, Ukraine, 15-17 September 1998. (RSB Mar’99 pp 28-30)

- Commission F Open Symposium; Aveiro, Portugal, 22-25 September 1998. (RSB Mar'99 pp 30-31)

- Workshop on Radio Methods for Studying Turbulence; Urbana , Illinois, USA,9-12 August 1999. (RSB Mar’99 pp 30-31)

In the list above, "RSB---" indicates the edition of the Radio Science Bulletin and page numbers where reports have been given.

Special mention should be made of the open symposium as this is the prime Commission F meeting held every three years in the year before an URSI General Assembly. The 1998 symposium, held in Aveiro, Portugal, was the eighth, the series being started in 1977. There were 70 participants from 22 countries and a total of 66 papers from 17 countries, including four keynote invited papers. There were eight oral sessions and a poster session, and the meeting maintained the excellent atmosphere of those before it. Whilst these meetings have been much appreciated by a loyal following, Commission F may wish to consider whether the next event should be enlarged.

Also some mention should be made of Climpara’98, held in Ottawa, which was the fourth in a series of meetings which link closely with ITU Working Parties 3J and 3M. This has been a valuable exchange in what has been a productive area of work. There were a total of 51 papers covering a range of mapping, modelling and measurement aspects of clear-air and precipitation. Having many people strongly involved in both (i) URSI Commission F and (ii) ITU Study Group 3 helps to give a strong sense of current application priorities to the former and scientific input to the latter. This is a valuable association for both organisations.

The Mode A meetings comprised:

- ISAP'96: International Symposium on Antennas and Propagation; Chiba, Japan, 24-27 September 1996. (RSB Sept’97 pp 14-15)

- ICAP'97: International Conference on Antennas and Propagation; Edinburgh, UK, 14-17 April 1997.

- Radio Africa'97: Second Regional Workshop on Radio Communications in Africa; Nairobi, Kenya, 4-8 August 1997. (RSB June’98 pp 30-32)

- IGARSS'97: International Geoscience and Remote Sensing Symposium; Singapore, 4-8 August 1997.

- URPS'97: Urban Radiowave Propagation Symposium; Tomsk, Russia, 2-4 September 1997. (RSB Dec’98 pp 17-18)

- IWTS'98: 1998 International Wireless and Telecommunications Symposium and Exhibition; Shah Alam, Malaysia, 11-15 May 1998. (RSB Mar’99 pp 21-22)

- EUSAR'98: European Conference on Synthetic Aperture Radar; Friedrichshafen, Germany, 25-27 May 1998. (RSB Dec’97 p 18)

- International Workshop "Day on Diffraction'98"; St. Petersburg, Russia, 2-4 June 1998. (RSB Dec’97 p 19)

- IGARSS'98: International Geoscience and Remote Sensing Symposium; Seattle, Washington, USA, 6-10 July 1998.

- COSPAR Scientific Assembly; Nagoya, Japan, 12-19 July 1998. (Council meeting: RSB Mar’99 pp 27-28)

- PIERS'98: Progress In Electromagnetic Research Symposium; Nantes, France, 13-17 July 1998.

- 10th Microcoll; Budapest, Hungary, 21-25 March 1999.

- International Workshop "Day on Diffraction'99"; St. Petersburg, Russia, 1-4 June 1999.

- IGARSS'99: International Geoscience and Remote Sensing Symposium; Hamburg, Germany, 28 June - 2 July 1999.

Particular mention should be made of the three IGARSS meetings. These are the largest remote sensing meetings (comparable in size with URSI GAs), primarily organised by IEEE GRSS, in which URSI Commission F has had responsibility for specific sessions. They cover some 76 topic areas of remote sensing and draw more than 1000 papers.

As probably for some other commissions, communication with individual scientists has been a problem for Commission F. Specific communications to the 43 National Committee Official Representatives (e.g. for voting purposes) has had only partial success, and in four cases there is no specific Commission F Representative. It is not clear as to what extent communication within the various 43 member countries is effective. Those who run individual meetings under the Commission F banner develop their own lists of people to contact, and of course make use of the URSI Radio Science Bulletin to advertise their meetings. The triennial Commission F Open Symposium uses the same methods. Setting up and frequently refreshing a Commission F Home Page on the internet might improve publicity somewhat.

The chapters for the Review of Radio Science have been mentioned above and the tutorial paper will appear in the URSI publication "Modern Radio Science, 1999"; thanks are expressed to Prof D Gjessing, Prof F Perez-Fontan, Dr Y Karasawa, Dr T Tjelta, Mr J P V Poiares Baptista, Prof P A Watston, Dr A J Illingworth, Prof C Kummerow, Dr K Okamoto, Dr J Hallikainen, Mr B Arbesser-Rastburg, Dr J Hjelmstad and Dr J van Zyl, and to Dr Y Furuhama as Commission F Editor for RRS.

A particular instance of communication (and publications) is in the preparation of the Disk of References associated with the six chapters in the URSI book entitled "Review of Radio Science 1996-1999" mentioned above under Scientific Programme. Not all commissions take part in this, but the 1996 Business Meetings of Commission F voted to do so. The major task was kindly undertaken for the commission by Dr Rod Olsen and the disk is now available. It comprises 1374 references from 24 countries as follows: Belarus, Belgium, Brazil, Canada, Czech Republic, China, Germany, Greece, Hungary, Italy, Japan, Netherlands, Nigeria, Norway, Poland, Portugal, Russia, South Africa, Switzerland, Sweden, Taiwan, Ukraine, UK and USA. Thanks are also due to those National Representatives who contributed.

It has been a busy three years for the commission and I am glad to have served as chairman.

Martin Hall.